阅读说明：本技术 一种聚四氟乙烯复合过滤材料 (Polytetrafluoroethylene composite filtering material ) 是由 肖平 肖忠良 蔡醇洋 唐毅 李慧 苏鉴 于 2020-03-31 设计创作，主要内容包括：本发明涉及空气过滤领域,具体涉及一种聚四氟乙烯复合过滤材料。所述聚四氟乙烯复合过滤材料包括支撑层和聚四氟乙烯薄膜层,所述支撑层为镀银碳纳米材料改性熔喷无纺布。所述聚四氟乙烯复合过滤材料通过对镀银碳纳米材料改性的树脂材料采用熔喷法在聚四氟乙烯薄膜表面熔喷成纤制备得到。本发明的聚四氟乙烯复合过滤材料将过滤与杀菌功能结合在一起,具有较高过滤效率和过滤精度,并具有杀菌、杀病毒的作用,具有很好的隔离效果,极大的延长了过滤材料的使用寿命。(The invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material. The polytetrafluoroethylene composite filter material comprises a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nano material modified melt-blown non-woven fabric. The polytetrafluoroethylene composite filter material is prepared by melt-blowing a resin material modified by a silver-plated carbon nano material on the surface of a polytetrafluoroethylene film by a melt-blowing method to form fibers. The polytetrafluoroethylene composite filter material combines the filtering and sterilizing functions, has higher filtering efficiency and filtering precision, has the functions of sterilizing and killing viruses, has good isolation effect, and greatly prolongs the service life of the filter material.)

1. The polytetrafluoroethylene composite filter material is characterized by comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nano material modified melt-blown non-woven fabric.

2. The polytetrafluoroethylene composite filter material as set forth in claim 1, wherein said support layer has a thickness of 80 to 130 μm.

3. The polytetrafluoroethylene composite filter material according to claim 1 or 2, wherein the silver-plated carbon nanomaterial-modified melt-blown nonwoven fabric is one or more of silver-plated carbon nanomaterial-modified PP melt-blown nonwoven fabric, silver-plated carbon nanomaterial-modified PET melt-blown nonwoven fabric, and silver-plated carbon nanomaterial-modified PA melt-blown nonwoven fabric.

4. The polytetrafluoroethylene composite filter material according to any one of claims 1 to 3, wherein said silver-plated carbon nanomaterial is silver-plated graphene oxide, silver-plated single-walled carbon nanotubes, or silver-plated fullerene.

5. A polytetrafluoroethylene composite filter material according to any one of claims 1 to 4, wherein said silver-plated carbon nanomaterial is prepared by plating silver on a carbon nanomaterial substrate using a pulsed laser deposition method.

6. The polytetrafluoroethylene composite filter material as set forth in claim 5, wherein the pulse frequency of the pulse laser deposition method is 10-15Hz, the temperature of the substrate during deposition is 380-500 ℃ and the deposition time is 10-15 min.

7. A polytetrafluoroethylene composite filter material according to any one of claims 1 to 6, wherein said polytetrafluoroethylene film has a thickness of 5 to 50 μm, an average pore diameter of 0.1 to 1 μm, and a porosity of 80 to 90%.

8. The polytetrafluoroethylene composite filter material according to any one of claims 1 to 7, wherein the polytetrafluoroethylene composite filter material is prepared by melt-blowing a resin material modified by silver-plated carbon nanomaterials on the surface of a polytetrafluoroethylene film by a melt-blowing method to form fibers, and preferably, the resin material is PP resin, PET resin or PA resin.

9. The polytetrafluoroethylene composite filter material as set forth in claim 8, wherein the silver-plated carbon nanomaterial-modified resin material is prepared by mixing a silver-plated carbon nanomaterial with a resin material in a mass ratio of 3-8: 100, and mixing uniformly to obtain the product.

10. The polytetrafluoroethylene composite filter material according to claim 8 or 9, wherein the polytetrafluoroethylene film is a pretreated polytetrafluoroethylene film, and the pretreatment is radiation treatment, plasma treatment or high-temperature treatment.

Technical Field

The invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material.

Background

The safety of human beings is always threatened by various infectious diseases caused by the transmission of viruses and bacteria through air. Wearing a mask is a commonly used effective way to prevent viral infection and spread. After bacteria and viruses are blocked by the common protective mask through the filter medium, the bacteria and the viruses still exist in the filter medium, and the common protective mask also has the chance of infecting human beings under certain conditions. Therefore, the air purification filter material with higher filtering efficiency and filtering precision and sterilization and virus killing functions better meets the requirements of human health.

The polytetrafluoroethylene film is a flexible and elastic microporous material, has high porosity, uniform pore size distribution, air permeability and water impermeability, can be used for air dust removal, sterilization filtration and the like, and has the outstanding advantages that many traditional filtration membranes do not have. At present, a filtering material taking a polytetrafluoroethylene microporous film as a filtering layer has small breathing resistance and high filtering efficiency, mainly acts in a physical separation mode, and does not have a sterilization effect. After bacteria and viruses are blocked by the filter medium, the bacteria and the viruses still exist in the filter medium, and the risk of invading human beings still exists.

The carbon nano material is a carbon material with at least one dimension less than 100nm of dispersed phase dimension, has excellent optical, electrical and mechanical properties, and has important application prospects in the aspects of materials science, energy, biomedicine, drug delivery and the like. At present, carbon nanomaterials such as graphene oxide and carbon nanotubes are reported to be used as a filter material having antibacterial activity, but the antibacterial activity of the carbon nanomaterials is not high enough regardless of the graphene oxide and the carbon nanotubes. The nano silver has good antibacterial and inactivation characteristics, and the plating of silver ions on the surface of graphene or carbon nano tubes is an effective method for improving the antibacterial activity of the carbon nano material, but the silver ions are easy to gather in the silver-plated carbon nano material obtained by chemical plating, so that the improvement of the antibacterial activity is limited.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the polytetrafluoroethylene composite filter material for air purification, which can effectively filter PM2.5, aerosol containing bacteria and viruses and other extremely fine particles, and has high resistance to bacteria and viruses, good air permeability and good adsorptivity.

Specifically, in order to achieve the above purpose, the invention adopts the following technical scheme:

a polytetrafluoroethylene composite filter material comprises a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nano material modified melt-blown non-woven fabric.

Preferably, in the polytetrafluoroethylene composite filter material, the thickness of the support layer is 80-130 μm.

Preferably, in the polytetrafluoroethylene composite filter material, the silver-plated carbon nano-material modified melt-blown non-woven fabric is one or more of silver-plated carbon nano-material modified PP melt-blown non-woven fabric, silver-plated carbon nano-material modified PET melt-blown non-woven fabric and silver-plated carbon nano-material modified PA melt-blown non-woven fabric.

Preferably, in the polytetrafluoroethylene composite filter material, the silver-plated carbon nanomaterial is silver-plated graphene oxide, silver-plated single-walled carbon nanotube or silver-plated fullerene.

Preferably, in the polytetrafluoroethylene composite filter material, the silver-plated carbon nanomaterial is prepared by plating silver on a carbon nanomaterial substrate by a pulsed laser deposition method.

Preferably, in the polytetrafluoroethylene composite filter material, the pulse frequency of the pulse laser deposition method is 10-15Hz, the temperature of the substrate in the deposition process is 380-500 ℃, and the deposition time is 10-15 min.

Preferably, in the polytetrafluoroethylene composite filter material, the thickness of the polytetrafluoroethylene film is 5-50 μm, the average pore diameter is 0.1-1 μm, and the porosity is 80-90%.

Preferably, in the above polytetrafluoroethylene composite filter material, the polytetrafluoroethylene composite filter material is prepared by melt-blowing a resin material modified by a silver-plated carbon nanomaterial on the surface of a polytetrafluoroethylene film by a melt-blowing method to form fibers, and further preferably, the resin material is PP resin, PET resin or PA resin.

Preferably, in the polytetrafluoroethylene composite filter material, the silver-plated carbon nanomaterial-modified resin material is prepared by mixing a silver-plated carbon nanomaterial and a resin material in a mass ratio of (3-8): 100, and mixing uniformly to obtain the product.

Preferably, in the polytetrafluoroethylene composite filter material, the polytetrafluoroethylene film is a pretreated polytetrafluoroethylene film, and the pretreatment is radiation treatment, plasma treatment or high-temperature treatment.

The invention also provides application of the polytetrafluoroethylene composite filter material in air purification equipment or a mask.

According to the invention, the polytetrafluoroethylene microporous film with the characteristics of high air permeability and high filtering efficiency and the silver-plated carbon nano material modified melt-blown non-woven fabric with high antibacterial activity are compounded on line to obtain the polytetrafluoroethylene composite filtering material, the filtering and sterilizing functions are combined together, so that the composite material has high filtering efficiency, good water resistance and air permeability, and has the functions of sterilizing and killing viruses, a good isolation effect is achieved, the service life of the filtering material is greatly prolonged, and the viscosity of the polytetrafluoroethylene film can be effectively improved after the polytetrafluoroethylene film is pretreated.

The beneficial effects of the invention are mainly as follows:

(1) the polytetrafluoroethylene composite filter material utilizes the small aperture and high porosity of the polytetrafluoroethylene microporous membrane, and can effectively isolate PM2.5 particles and bacterial viruses while keeping smooth breathing;

(2) the silver-plated carbon nano material modified melt-blown non-woven fabric used in the polytetrafluoroethylene composite filter material has certain sterilization capacity, large specific surface area and strong adsorption capacity, increases the probability of contact of nano silver and bacterial liquid, so that a strong antibacterial effect is generated;

(3) the polytetrafluoroethylene composite filter material is prepared by on-line compounding, shortens the process flow, ensures the air permeability of the filter material, and simultaneously can improve the yield per unit time, save energy and reduce cost.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the scope of the present invention is not limited thereto.

The examples, where specific experimental procedures or conditions are not indicated, were carried out according to the procedures or conditions of the conventional experimental procedures described in the literature in the field. The reagents and instruments used are not indicated by manufacturers, and can be purchased in the market.

The polytetrafluoroethylene film used in the examples is a CGPMH series PTFE microporous film of Zhonghao Chen optical chemical research institute, the thickness is 30 μm, the average pore diameter is 0.25 μm, and the porosity is 85%; graphene oxide, single-walled carbon nanotubes and fullerene are purchased from Nanjing pioneer nanomaterial science and technology Limited; PP resin, PET resin, and PA resin are available from DuPont, USA.

Example 1

Embodiment 1 provides a polytetrafluoroethylene composite filter material for air purification, which comprises a support layer and a polytetrafluoroethylene film layer, wherein the support layer is a silver-plated single-walled carbon nanotube modified PP melt-blown non-woven fabric, and the thickness of the support layer is 100 μm.

The preparation method of the polytetrafluoroethylene composite filter material comprises the following steps:

(1) single-walled carbon nanotube pretreatment: weighing 5g of single-walled carbon nanotube, adding the single-walled carbon nanotube into a three-neck flask containing 200mL of mixed solution (mass ratio is 70:30) of concentrated nitric acid and concentrated sulfuric acid, heating and refluxing for 5 hours at 120 ℃ in an oil bath, cooling, then carrying out suction filtration, washing with deionized water and drying;

(2) silver plating: under the condition of room temperature, high-purity metallic silver is taken as a target material, the pretreated single-walled carbon nanotube is taken as a substrate, and N₂Atmosphere, pulsed laserThe pulse frequency of light is selected to be 10Hz, the temperature of the substrate is maintained at 400 ℃ in the deposition process, and the deposition time is 10 min;

(3) and (3) mixing the silver-plated single-walled carbon nanotube obtained in the step (2) with PP resin in a mass ratio of 3: 100, uniformly mixing to obtain 3% silver-plated single-walled carbon nanotube modified PP resin;

(4) pretreating a polytetrafluoroethylene film: putting the polytetrafluoroethylene film into a plasma generator, pumping the system to 1.33Pa, introducing trace argon, adjusting the vacuum degree to 133.32Pa, and electrifying for 15 min;

(5) compounding: laying a layer of polytetrafluoroethylene film which is processed by low-temperature plasma on a receiving roller of a non-woven melt-blowing machine, extruding 3% silver-plated single-walled carbon nanotube modified PP resin from a spinneret orifice of the melt-blowing machine in a molten state, and uniformly spraying the PP resin on one side of the polytetrafluoroethylene film under the high-speed traction of airflow to obtain the polytetrafluoroethylene composite filter material, wherein the hot air temperature is 200 ℃, the receiving interval is 12cm, the traversing speed is 0.5m/min, and the extrusion amount is 40 g/min.

Example 2

Embodiment 2 provides a polytetrafluoroethylene composite filter material for air purification, including a support layer and a polytetrafluoroethylene film layer, the support layer is silver-plated graphene oxide modified PP melt-blown non-woven fabric, and its thickness is 100 μm.

The preparation method of the polytetrafluoroethylene composite filter material comprises the following steps:

(1) pretreatment of graphene oxide: weighing 2g of graphene oxide, adding the graphene oxide into a three-neck flask containing 200mL of mixed solution (mass ratio of 70:30) of concentrated nitric acid and concentrated sulfuric acid, heating and refluxing for 5 hours in an oil bath at 120 ℃, cooling, then carrying out suction filtration, washing with deionized water and drying;

(2) silver plating: under the condition of room temperature, high-purity metal silver is used as a target material, pretreated graphene oxide is used as a substrate, and N is₂Selecting the pulse frequency of the pulse laser at 10HZ, maintaining the temperature of the substrate at 400 ℃ in the deposition process, and depositing for 10 min;

(3) mixing the silver-plated graphene oxide obtained in the step (2) with PP resin according to a mass ratio of 3: 100, uniformly mixing to obtain 3% silver-plated graphene oxide modified PP resin;

(4) pretreating a polytetrafluoroethylene film: putting the polytetrafluoroethylene film into a plasma generator, pumping the system to 1.33Pa, introducing trace argon, adjusting the vacuum degree to 133.32Pa, and electrifying for 15 min;

(5) compounding: a layer of polytetrafluoroethylene film after plasma treatment is laid on a receiving roller of a non-woven melt-blowing machine, 3% silver-plated graphene oxide modified PP resin is extruded from a spinneret orifice of the melt-blowing machine in a molten state, and is uniformly sprayed on one side of the polytetrafluoroethylene film under the high-speed traction of airflow to obtain the polytetrafluoroethylene composite filter material, wherein the hot air temperature is 200 ℃, the receiving interval is 12cm, the traversing speed is 0.5m/min, and the extrusion amount is 40 g/min.

Example 3

Embodiment 3 provides a polytetrafluoroethylene composite filter material for air purification, including a support layer and a polytetrafluoroethylene film layer, the support layer is a silver-plated fullerene modified PP melt-blown nonwoven fabric, and the thickness thereof is 100 μm.

The preparation method of the polytetrafluoroethylene composite filter material comprises the following steps:

(1) pretreatment of fullerene: weighing 5g of fullerene, adding the fullerene into a three-neck flask containing 200mL of mixed solution (mass ratio is 70:30) of concentrated nitric acid and concentrated sulfuric acid, heating and refluxing for 5 hours at 120 ℃ in an oil bath, cooling, then carrying out suction filtration, washing with deionized water and drying;

(2) silver plating: under the condition of room temperature, high-purity metal silver is taken as a target material, pretreated fullerene is taken as a substrate, and N₂Selecting the pulse frequency of the pulse laser at 10HZ, maintaining the temperature of the substrate at 400 ℃ in the deposition process, and depositing for 10 min;

(3) and (3) mixing the silver-plated fullerene obtained in the step (2) with PP resin in a mass ratio of 3: 100, uniformly mixing to obtain 3% silver-plated fullerene modified PP resin;

(4) pretreating a polytetrafluoroethylene film: placing the polytetrafluoroethylene film in a propylene monomer, and then irradiating for 15min by gamma rays;

(5) compounding: laying a layer of irradiated polytetrafluoroethylene film on a receiving roller of a non-woven melt-blowing machine, extruding 3% silver-plated fullerene modified PP resin from a spinneret orifice of the melt-blowing machine in a molten state, and uniformly spraying the PP resin on one side of the polytetrafluoroethylene film under the high-speed traction of airflow to obtain the polytetrafluoroethylene composite filter material, wherein the hot air temperature is 200 ℃, the receiving interval is 12cm, the transverse speed is 0.5m/min, and the extrusion amount is 40 g/min.

Example 4

Embodiment 4 provides a polytetrafluoroethylene composite filter material for air purification, including a support layer and a polytetrafluoroethylene film layer, the support layer is silver-plated graphene oxide modified PP melt-blown nonwoven fabric, and its thickness is 85 μm.

The preparation method of the polytetrafluoroethylene composite filter material comprises the following steps:

steps (1) to (2) were the same as in example 2

(3) Mixing the silver-plated graphene oxide obtained in the step (2) with PP resin according to a mass ratio of 5: 100, uniformly mixing to obtain 5% silver-plated graphene oxide modified PP resin;

(4) pretreating a polytetrafluoroethylene film: putting the polytetrafluoroethylene film into a plasma generator, pumping the system to 1.33Pa, introducing trace argon, adjusting the vacuum degree to 133.32Pa, and electrifying for 15 min;

(5) compounding: a layer of polytetrafluoroethylene film which is processed by plasma is laid on a receiving roller of a non-woven melt-blowing machine, 5% silver-plated graphene oxide modified PET resin is extruded from a spinneret orifice of the melt-blowing machine in a molten state, and is uniformly sprayed on one side of the polytetrafluoroethylene film under the high-speed traction of airflow to obtain the polytetrafluoroethylene composite filter material, wherein the hot air temperature is 200 ℃, the receiving interval is 12cm, the traversing speed is 0.5m/min, and the extrusion amount is 30 g/min.

Example 5

Embodiment 1 provides a polytetrafluoroethylene composite filter material for air purification, which comprises a support layer and a polytetrafluoroethylene film layer, wherein the support layer is a silver-plated single-walled carbon nanotube modified PA melt-blown non-woven fabric, and the thickness of the support layer is 120 μm.

The preparation method of the polytetrafluoroethylene composite filter material comprises the following steps:

steps (1) to (2) were the same as in example 2

(3) Mixing the silver-plated graphene oxide obtained in the step (2) with PA resin according to a mass ratio of 8: 100, uniformly mixing to obtain 8% silver-plated graphene oxide modified PA resin;

(4) pretreating a polytetrafluoroethylene film: placing the polytetrafluoroethylene film in a propylene monomer, and then irradiating for 15min by gamma rays;

(5) compounding: laying a layer of polytetrafluoroethylene film after radiation treatment on a receiving roller of a non-woven melt-blowing machine, extruding 8% of silver-plated single-walled carbon nanotube modified PA resin from a spinneret orifice of the melt-blowing machine in a molten state, and uniformly spraying the PA resin on one side of the polytetrafluoroethylene film under the high-speed traction of airflow to obtain the polytetrafluoroethylene composite filter material, wherein the hot air temperature is 200 ℃, the receiving interval is 12cm, the traversing speed is 0.5m/min, and the extrusion amount is 52 g/min.

Comparative example 1

Comparative example 1 provides a polytetrafluoroethylene composite filter material for air purification, which comprises a support layer, a silver-plated graphene layer and a polytetrafluoroethylene film layer, wherein the support layer is a PP melt-blown non-woven fabric, the thickness of the PP melt-blown non-woven fabric is 100 micrometers, and the thickness of the silver-plated graphene layer is 5 micrometers.

The preparation method of the polytetrafluoroethylene composite filter material comprises the following steps:

(1) preparing PP melt-blown non-woven fabric: extruding PP resin from a spinneret orifice of a melt-blowing machine in a molten state, and uniformly spraying the PP resin on a receiving roller under the high-speed traction of airflow to obtain PP melt-blown non-woven fabric, wherein the temperature of hot air is 200 ℃, the receiving interval is 12cm, the traversing speed is 0.5m/min, and the extrusion amount is 40 g/min;

(2) preparing a silver-plated graphene oxide film: the method for silver plating of the graphene oxide is the same as the steps (1) to (2) in the embodiment 2, and then the obtained silver-plated graphene oxide is dissolved in an absolute ethyl alcohol solution, and the silver-plated graphene oxide film is obtained by suction filtration;

(3) pretreating a polytetrafluoroethylene film: putting the polytetrafluoroethylene film into a plasma generator, pumping the system to 1.33Pa, introducing trace argon, adjusting the vacuum degree to 133.32Pa, and electrifying for 15 min;

(4) and laminating and compounding the PP melt-blown non-woven fabric, the graphene film and the polytetrafluoroethylene film to obtain the polytetrafluoroethylene composite filter material.

Comparative example 2

Comparative example 2 provides a polytetrafluoroethylene composite filter material for air purification, including a support layer and a polytetrafluoroethylene film layer, the support layer is silver-plated graphene oxide modified PP melt-blown non-woven fabric, and its thickness is 100 μm.

The preparation method of the polytetrafluoroethylene composite filter material comprises the following steps:

steps (1) to (4) were the same as in example 2

(5) Compounding: extruding 3% silver-plated graphene oxide modified PP resin from a spinneret orifice of a melt-blowing machine in a molten state, and uniformly spraying the PP resin on a receiving roller under the high-speed traction of airflow to obtain the PP melt-blown non-woven fabric, wherein the hot air temperature is 200 ℃, the receiving interval is 12cm, the traversing speed is 0.5m/min, and the extrusion amount is 40 g/min. Uniformly coating the PUR adhesive on one side of the silver-plated graphene oxide modified PP melt-blown non-woven fabric, wherein the coating weight is 1.6g/m²And overlapping the adhesive coating surface of the silver-plated graphene oxide modified PP melt-blown non-woven fabric with the polytetrafluoroethylene film subjected to low-temperature plasma treatment, and performing pressure and heat treatment to joint the adhesive coating surface and the polytetrafluoroethylene film, wherein the pressure and heat treatment is 2.1MPa and the temperature is 55 ℃, and finally, the polytetrafluoroethylene composite filter material of the comparative example is obtained by curing at the temperature of 58 ℃ for 10 hours.

Test examples

The air permeability, filtration efficiency and antibacterial ratio of the polytetrafluoroethylene composite filter materials prepared in the above examples and comparative examples were measured, and the results are shown in table 1. Wherein, the air permeability test is carried out according to GBT 1038-.

TABLE 1

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.